Wyniki wyszukiwania - BazTech

1

Combustion comparative analysis of pyrolysis oil and diesel fuel under constant-volume conditions

Szwaja Magdalena, Szymanek Arkadiusz

Combustion Engines

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2023

|

R. 62, nr 4

90--96

EN

The article discusses the research results on the combustion of pyrolysis oil derived from the pyrolysis of HDPE plastics after its distillation. The tests were carried out in a constant-volume combustion chamber in conditions similar to those in a compression-ignition engine with a compression ratio of 17.5:1. The phases of premixed and diffusion combustion and the ignition lag were determined. Then, diesel fuel combustion tests were performed under similar pressure-temperature conditions. Comparative analysis was used to draw conclusions as follows: the percentage fraction of heat released from the premixed combustion phase to total heat for pyrolysis oil was nearly 22%, whereas this parameter is 15% for diesel fuel, the maximum combustion rate for the premixed combustion phase for pyrolysis oil was approximately 27% higher than the premixed combustion rate for diesel fuel, the ignition lag for pyrolysis oil was slightly longer compared to that for diesel fuel. The presented parameters have a significant impact on both the development of combustion and the thermal efficiency of the internal combustion engine. Summing up, one can conclude, that pyrolysis oil can be applied as a substitute for diesel fuel both as a single fuel or blend component with it.

2

Influence of the primary components of the high-speed train on fire heat release rate

Zhou Yuanlong, Bi Haiquan, Wang Honglin

Archives of Thermodynamics

|

2023

|

Vol. 44, no 1

37--61

EN

A numerical model of the high-speed train carriage fire is established in this study. The influence of ceilings, sidewalls, luggage racks, seats, and floors on the heat release rate (HRR) of the high-speed train is studied by numerical methods. The results indicate that the heat release rate per unit area (HRRPUA) of ceiling and seat material dramatically influences the peak HRR and the time to peak HRR of train carriage fire. When the peak HRRPUA of interior ceiling material 1 decreases from 326 to 110 kW/m2 , the peak HRR of the high-speed train fire decreases from 36.4 to 16.5 MW, with a reduction ratio of 54.7%. When seat materials with low HRRPUA are used, the peak HRR reduction ratio is 44.8%. The HRRPUA of the sidewall, luggage rack, and floor materials has little effect on the peak HRR of the carriage fire. However, the non-combustible luggage rack can delay the time when the HRR reaches its peak.

3

Wpływ wodorotlenku glinu (III) i wodorotlenku magnezu (II) oraz związków fosforoorganicznych na palność materiałów epoksydowych

Staszko Sebastian, Półka Marzena

Materiały Budowlane

|

2022

|

nr 10

74--78

PL

W artykule zaprezentowano wpływ Mg(OH)2, Al(OH)3 oraz Roflamu F5 i Roflamu B7 na właściwości palne utwardzonej żywicy epoksydowej Epidian 5. Po analizie szybkości wydzielania ciepła w kalorymetrze stożkowym oraz analizie termograwimetrycznej stwierdzono, że wprowadzone dodatki są skutecznymi antypirenami testowanych materiałów epoksydowych. Najmniejszą wartość maksymalnej szybkości wydzielania ciepła zanotowano dla próbki składającej się z Epidianu 5 oraz 10% wag. Roflamu F5 oraz 5% wag. Al(OH)3.

EN

The article presents the effect of Mg(OH)2, Al(OH)3, Roflam F5 and Roflam B7 on the flammability properties of the hardened epoxy resin Epidian 5. After analyzing the heat release rate in the cone calorimeter and thermogravimetric analysis, it was found that the introduced additives are effective antirenes of the tested epoxy materials. The lowest value of the maximum heat release rate was recorded for the sample consisting of Epidian 5 and 10 wt.% of Roflam F5 and 5 wt. Al(OH)3.

4

Ocena reakcji na ogień wyrobów budowlanych na podstawie badań małej skali w kalorymetrze stożkowym

Papis Bartłomiej

Materiały Budowlane

|

2021

|

nr 1

45--47

5

Evaluation of the heat release rate during the combustion process in the diesel engine chamber powered with fuel from renewable energy sources

Bednarski M., Orliński P., Wojs M., Gis M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2020

|

Vol. 68, nr 6

1333--1339

EN

The article describes the results of combustion of a mixture of PCOME (purified cooking oil esters) and bioethanol in the compression ignition Perkins 1104C-44 engine. The engine was prepared for use with the classic type of fuel – diesel oil, not biofuels. That is why bioethanol was added to ester in tests so that the basic physicochemical properties of the obtained mixture were as close as possible to diesel fuel. Thanks to this, the use of such fuel in the future would not require reworking or adjusting the settings of selected elements of the engine power supply system. During this case study, the engine performance and heat release rate were analyzed. For comparison, tests were carried out while powering the engine with ester fuel, 10 and 20 per cent mixtures of bioethanol and PCOME. The speed and load characteristics for each fuel were determined. This article presents selected characteristics where the biggest differences were noticed.

6

Komputerowe modele rozprzestrzeniania się płomieni i gaszenia wodą, w ocenie skutków rozwoju pożaru oraz skuteczności działania instalacji tryskaczowych

Krauze Andrzej

Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej

|

2019

|

Nr 72 (tom 4)

45--54

PL

Równania przepływu płynu, które obrazują rozprzestrzenianie się gorących gazów pożarowych były walidowane i sprawdzone pod względem przyjętych przybliżeń. Niemniej procesy spalania oraz rozkładu termicznego materiałów palnych nadal pozostają zagadnieniem trudnym do modelowania. Przy wykonywaniu analiz komputerowych z zakresu inżynierii bezpieczeństwa pożarowego, często istnieje konieczność oceny wpływu tryskaczy na rozwój pożaru. Obecnie modelowanie efektu gaśniczego tryskaczy wykonuje się najczęściej poprzez modyfikację szybkości uwalniania ciepła z pożaru (czyli krzywej HRR – z ang. Heat Release Rate) oraz założenie ograniczonej powierzchni pożaru. W artykule przedstawiono możliwości wykorzystania zaawansowanych modeli pirolizy i gaszenia wodą do komputerowej oceny wpływu tryskaczy na rozwój pożaru. Omówiono opracowane dotychczas metody modelowania rozprzestrzeniania się płomieni opracowane dla programu Fire Dynamics Simulator.

EN

The equations of liquid flow describing the fire spread of hot fire gases were validated and tested in respect of assumed approximation. However, the processes of combustion and the thermal decomposition of flammable materials are still very difficult to simulate. The expected heat release rate (HRR) is the most important element of the fire hazard evaluation in a building. During the computer analysis in the field of fire safety engineering, there Zeszyty Naukowe sgsp 2019, Nr 72/4/2019 46 Andrzej Krauze is a need to assess the influence of sprinkler systems on the fire development. At the moment, the simulation of the extinguishing effects of sprinklers is mainly done by the modification of the heat release rate (the curve of HHR) and the limitation of the fire zone. To evaluate the influence of sprinklers on the fire spread, the article presents the possibilities of some practical use of the advanced models of the pyrolysis and extinguishing with water. The methods of the fire spread simulation done for the Fire Dynamic Simulator have been described.

7

Investigation on fire potential of ventilation ducts

Jha Ankit, Amar Vinod, Tukkaraja Purushotham

Journal of Sustainable Mining

|

2019

|

Vol. 18, iss. 4

270--276

EN

Fires in underground mines can create dangerous conditions for personnel and cause severe damage to property. Because of the confined nature of the underground environment, these effects can escalate rapidly. In underground mines, air ducts/bags are used for ventilating narrow blind headings; these consist of combustible materials that have not been investigated thoroughly in terms of their fire potential and gas emissions. The primary objective of this study is to investigate the fire potential and emission factors for these ducts. A preliminary investigation was performed using differential scanning calorimetry and thermogravimetric analysis. These tests provide crucial information for duct samples including the melting point which is used for designing a novel experimental setup for combustion analysis. This setup was used to perform a combustion experiment at 350 °C, so that all specimens can achieve complete combustion. Furthermore, the heat release rate and emission factors were calculated; it was observed that heat release rate for all the specimens was identical because of similar oxygen consumption during the experiment. Sample B has the lowest emission factor among the four samples (A, B, C, D) tested in this study.

8

Design of fire scenarios for Australian underground hard rock mines - Applying data from full-scale fire experiments

Hansen Rickard

Journal of Sustainable Mining

|

2019

|

Vol. 18, iss. 4

163--173

EN

One of the most significant tools when designing fire safety in an underground mine is the design fire methodology. This paper presents a number of design fire scenarios which were developed from risk assessments and risk analysis where a deterministic approach was implemented and where the results from earlier full-scale fire experiments in underground mines and analysis were included in the process. The developed scenarios showed that for scenarios, in which ventilation flow was in the same direction as the fuel continuity, continued fire spread to all major components were provided and longer and intermittent periods which resulted in high heat release rates resulted, would present a considerable risk to underground personnel. It was also found that the inclination of the decline has little influence on the resulting heat release rate - despite the flame tilt - and that the design of the mining vehicles was found to effectively delay or even prevent the ignition of adjacent fuel items in a number of cases. The design fire scenarios developed will provide a key tool when evaluating fire protection measures in an underground mine.

9

Comparative study on combustion characteristics of lean premixed CH4/air mixtures in RCM using spark ignition and turbulent jet ignition in terms of orifices angular position change

Bueschke Wojciech, Skowron Maciej, Wisłocki Krzysztof, Szwajca Filip

Combustion Engines

|

2019

|

R. 58, nr 1

36--41

EN

The increase in ignitability consist a main aim of implementation of the turbulent jet ignition (TJI) in relation to the combustion of diluted charges. Such an ignition system has been introduced to the lean-burn CNG engine in the scope of GasOn-Project (Gas Only Internal Combustion Engines). In this study the impact of TJI application on the main combustion indexes has been investigated using RCM and analyzed on the bases of the indicating and optical observations data. The images have been recorded using LaVision HSS5 camera and post-processed with Davis software. Second part of the study based on indicating measurements consist the analysis of combustion regarding the variation in the geometry of pre-chamber nozzles. It has been noted, that combustion with TJI indicates significantly bigger flame luminescence and simultaneously - faster flame front development, than the combustion initiated with conventional SI. The positive impact of nozzles angular position on engine operational data has been found in the static charge movement conditions, regarding the combustion stability.

10

Application of Ion Current Measurement to Identification of Combustion Parameters in a Homogeneous Charge Compression Ignition Engine

Hunicz J., Filipek P., Sobiesiak A.

Metrology and Measurement Systems

|

2018

|

Vol. 25, nr 1

223--234

EN

This study examines the application of ion current measurements to the identification of heat release parameters inside the combustion chamber of a homogeneous charge compression ignition (HCCI) engine fuelled with gasoline. HCCI combustion was achieved with the use of exhaust gas trapping. Combustion parameters derived from the in-cylinder pressure and ion current measurements were compared and analysed. Ion current measurements were accomplished using the existing spark plug and a dedicated electronic circuit. The experiments were performed at a variable excess air ratio and a variable amount of trapped residuals. The results showed a good correlation between peak values of the ion current and heat release rate, except for the cases where a fuel-rich mixture was burnt. The computed ion current integral over the volume of the combustion chamber showed a good agreement with the heat released in the combustion chamber, however this parameter was found to be affected by the amount of trapped residuals. Combustion timing characteristic values computed using heat release and ion current were found to be correlated, however the relationship was not linear.

11

Analiza zagrożenia pożarowo-wybuchowego stwarzanego przez wybrane środki ochrony roślin wraz z oceną ich potencjalnego wpływu na środowisko

Kukfisz B.

Materiały Wysokoenergetyczne

|

2018

|

T. 10

13--21

PL

W artykule przedstawiono zagrożenia stwarzane przez wybrane środki ochrony roślin stosowane w rolnictwie zawierające substancje aktywne z grupy pyretroidów (lambda-cyhalotryna, beta-cyflutryna i deltametryna), które wytypowano na podstawie rejestru środków ochrony roślin dopuszczonych do obrotu zezwoleniem Ministra Rolnictwa i Rozwoju Wsi [1, 2]. Wyznaczono parametry wybuchowe stwarzane przez obłoki pyłów wybranych substancji i preparatów oraz zakwalifikowano je do odpowiednich klas wybuchowości [3, 4]. W zakresie zagrożenia pożarowego metodą kalorymetru stożkowego przy poziomym ułożeniu próbki przy obecności palnika pilotowego określono szybkość wydzielania ciepła [5].

EN

The article presents the threats posed by selected plant protection products used in agriculture containing active substances from the pyrethroid group (lambda-cyhalothrin, beta-cyfluthrin and deltamethrin), which were selected on the basis of the register of authorized plant protection products granted marketing authorization by the Ministry of Agriculture and Rural Development [1, 2]. Explosive parameters created by dust clouds of selected substances and preparations were determined and classified in appropriate explosion classes [3, 4]. In terms of flammability danger, values of heat release rate were determined on the basis of calorimetric analysis of specimens exposed in the horizontal orientation to controlled levels of irradiation with an external igniter [5].

12

Thermodynamic analysis of combustion events in the natural gas fuelled SI engine with VVT

Szwaja M., Mazuro P., Szwaja S.

Journal of KONES

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2018

|

Vol. 25, No. 4

421--427

EN

The main aim of the research was to investigate influence of overlap of the natural gas fuelled spark ignited engine on the following parameters: Indicated Mean Effective Pressure (IMEP), heat rate release including combustion phases (ignition lag, main combustion phase). The content of the study includes results from processing in-cylinder pressure measurements, heat release rate analysis, combustion phases, and finally the conclusions. The tests were carried out on the test bed including the single cylinder research engine with a displacement volume of 550 cm3. The engine was equipped with independent cam phasors for both intake and exhaust valves, but for this investigation, the exhaust valve timing was fixed (the exhaust cam centre line was fixed at -95 crank angle (CA) deg before Top Dead Centre) and intake valve timing was changed (the intake cam centre line was varied from 90 to 150 CA deg after Top Dead Centre). The overlap was changed in the range from 85 to 25 CA deg. 8 tests series were performed, each singular series consisted of 300 consecutive engine combustion cycles. As observed, by varying the valve overlap it contributes to significant change in the peak combustion pressure, peak of heat release rate, and combustion phases. Summing up, variable valve timing affects compression and expansion strokes by changing polytropic indexes due to various amounts of exhaust residuals trapped in the cylinder. It affects not only engine volumetric efficiency but also the heat release rate and IMEP, so it does engine performance. Thus, variable valve timing can be considered as valuable tool that can be applied to the natural gas fuelled internal combustion engine.

13

The influence of injection timing on the combustion characteristics for the heterogeneous combustion field using impinging injection

Kawakami T.

Journal of KONES

|

2018

|

Vol. 25, No. 3

283--288

EN

It is very important to achieve the low particulate and low emissions under high power operation conditions in practical industrial engine and turbine combustion. Several techniques for reducing the emissions have been proposed and a large amount of experimental data has been published. It is well known that the combustion field in practical industrial diesel engine are strongly influenced by the behaviour of injection, distribution of droplets and the premixed ratio of the combustion chamber. As the first step of this study, experiments have been carried out to examine the combustion characteristics of heterogeneous combustion field by using impinging injection and Split injection in a closed chamber. The combustion chamber is equipped with pintle type injection nozzles on each of the opposite walls along the length of the bomb. In this study, we call it “impinging injection” when the injection is performed at same time by two nozzles facing each other and “split injection” when the impinging injection is performed at two different timing. The main conclusions are as follows: 1) the most suitable conditions of injection timing exists for improving the maximum burning pressure and total burning time by using impinging injection; 2) the flame speed can be possible to control by using impinging injection timing from the ignition; 3) the heat release rate for Split injection is larger than that of standard impinging injection.

14

Analiza wpływu cynianów cynku i mączki keratynowej na właściwości palne materiału epoksydowego

Półka M., Kukfisz B., Kulik A.

Polimery

|

2017

|

T. 62, nr 10

764--771

PL

Oceniano wpływ wybranych środków uniepalniających na właściwości pożarowe kompozytów na bazie żywicy epoksydowej Epidian 5 (Ep 5). Żywicę epoksydową modyfikowano ogniochronnie za pomocą hydroksycynianu(IV) cynku (ZHS), cynianu(IV) cynku (ZS) oraz materiału odpadowego – mączki keratynowej (KR). Metodą kalorymetru stożkowego wyznaczano szybkości wydzielania ciepła i dymu z palących się próbek kompozytów poddanych działaniu strumienia cieplnego o gęstości 30 kW/m2 i 50 kW/m2. Przeprowadzono też analizę termograwimetryczną otrzymanych niemodyfikowanych oraz modyfikowanych ogniochronnie materiałów. Stwierdzono, że dodatki ZS i ZHS, wprowadzone do utwardzonej żywicy Ep 5, skutecznie zmniejszają szybkość wydzielania ciepła z palących się próbek i mogą w istotnym stopniu ograniczyć rozprzestrzenianie się pożaru.

EN

This paper analyses the impact of selected flame retardant additives on the combustibility and fire properties of epoxy materials based on Epidian 5 (Ep 5). The prepared epoxy resin was modified to increase its fire resistance using zinc hydroxystannate(IV) (ZHS), zinc stannate(IV) (ZS) and waste material – keratin powder (KR). The cone calorimeter was used to determine the heat and smoke release rates of burning composite samples using heat flux density of 30 and 50 kW/m2. Also, thermogravimetric analysis of the flame retardant modified and non-modified epoxy materials was performed. It was found that fire retardant additives ZS and ZHS added to the epoxy resin Ep 5 effectively decreased the heat release rate of the burning samples of cured resin and could significantly limit the spread of fire.

15

Rail Vehicle Peak Heat Release Rate Estimation

Tooley D.

Problemy Kolejnictwa

|

2016

|

Z. 173

65--72

EN

This paper describes the various methods used to estimate vehicle energy released in the event of a rail vehicle flashover fire. It considers real scale test data and whether it can be applied to other designs. It also considers the calculation methods used in a variety of applications including estimation based on heat content, the Boon-Chiam and Heat Release Rate per Unit Area (HRRPUA or Duggan) methods. It describes features and gives an overview of each calculation method considered. It discusses the energy required to generate flashover in a rail vehicle. It discusses limitations to confidence in calculation of peak release rate. It proposes some ideas for future work programmes to mitigate them as far as is possible. This includes the possibility of using a validated CFD analysis method. CFD analysis could also determine a greater understanding of what may happen in a tunnel in the event of a vehicle flashover fire. It is considered feasible to use the concepts proposed in this paper to develop an outline calculation methodology, but it is noted that because of infrastructure variables, it may not be possible to define a fully standardised process.

PL

Artykuł opisuje różne metody stosowane do szacowania energii pojazdu wydzielanej w przypadku gwałtownego rozgorzenia (flashover) w pojeździe ko lejowym. Autor przytacza dane z badań w skali rzeczywistej i rozważa, czy mogą być one wykorzystane do innych celów. Podaje również metody obliczania używane w różnych aplikacjach, takich jak: szacunki na podstawie zawartości ciepła, metoda Boon-Chiam’a i obliczanie gęstości mocy pożaru Duggana (HRRPUA). Artykuł zawiera przegląd i opis cech charakterystycznych wymienionych metod obliczania. Charakteryzuje ilość energii potrzebnej do stworzenia rozgorzenia w pojeździe kolejowym oraz ograniczenia dotyczące pewności obliczania największego wydzielanego ciepła. W artykule zaproponowano koncepcje przyszłych programów prac w celu umożliwienia korzystania z uznanej metody analizy CFD (obliczeniowej mechaniki płynów). Analiza ta, umożliwia zrozumienie, co może się zdarzyć w tunelu podczas rozgorzenia w pojeździe kolejowym. Koncepcje zaproponowane w artykule mogą być wykorzystane do opracowania metody obliczeń, jednak ze względu na zmienne parametry infrastruktury, może nie będzie możliwe zdefiniowanie procedury w pełni znormalizowanej.`

16

Nonlinear Regression Model for Ride on Railway

Żółtowski B., Castaneda L., Żółtowski M.

Problemy Kolejnictwa

|

2016

|

Z. 173

73--82

EN

The portable diagnosis system – SPD – evaluates the safety and ride quality aspects of the railway vehicles and the technical condition of the rail-vehicle interface. The objective of this article is to estimate the nonlinear regression model associated with the ride quality or motion behavior, by applying fuzzy clustering algorithms to the geometric data obtained from the technical condition of the railway-vehicle interface and measuring quasi-static lateral acceleration y*qst in different vehicles. The performance will be evaluated by comparing the measured acceleration y*qst with the acceleration calculated in our model y*qstM for 15 different vehicles. The obtained results will be then compared with the results of the multiple linear regression model used previously for the same purpose.

PL

Przenośny system diagnostyczny – SPD ocenia aspekty bezpieczeństwa i jakości biegu pojazdów kolejowych oraz stanu technicznego pojazdu kolejowego. Celem niniejszego artykułu jest oszacowanie nieliniowego modelu regresji związanego z zachowaniem jakości jazdy, przez zastosowanie rozmytego algorytmu klastrowania danych geometrycznych stanu technicznego pojazdu kolejowego i pomiary quasi-statyczne przyspieszeń poprzecznych pojazdów szynowych. Będzie to ocena porównawcza zmierzonego realnego przyspieszenia z przyspieszeniem obliczonym skonfigurowanego modelu dla 15 różnych pojazdów. Uzyskane wyniki będą porównane z wynikami modelu liniowej regresji wielokryterialnej, które były dotychczas w tym celu stosowane.

17

Influence of the Ignition Source on Passenger Seat Burning

Radziszewska-Wolińska J. M.

Problemy Kolejnictwa

|

2016

|

Z. 171

67--77

EN

The paper describes the results of first stage of studies conducted in the framework of a project funded by Railway Institute. The first stage of the work refers to tests on the furniture calorimeter according to the draft of the new European standard constituting a modification of the method according to EN 45545-2: 201. Above tests performed on different upholstered passenger seats, which met the PN and the UIC fire requirements, showed that none of the standard seats mets current requirement MARHE for HL3 category. Next part presents the results of research on the furniture calorimeter using different ignition sources (paper bag, travel bag, gas burner) with a power of 7 kW to 67 kW. Results showed that, for the MARHE, HRR and TSP a logarithmic increase in value with the increase of the power sources of ignition was achieved. At the same time it was found that the maximum values of HRR and TSP occurred in less than 4 minutes after seat ignition, which is a very important time for the evacuation of passengers.

PL

Artykuł opisuje wyniki badań przeprowadzonych w pierwszym etapie projektu finansowanego ze środków Instytutu Kolejnictwa. Pierwszy etap pracy dotyczy badań na kalorymetrze meblowym według projektu nowej normy europejskiej, stanowiącej modyfikację metody badawczej według EN 45545-2: 2013. Testy wykonane dla różnych tapicerowanych foteli, spełniających wymagania ogniowe PN oraz UIC wykazały, że żaden ze standardowych foteli nie spełnia aktualnych wymagań parametru MARHE dla kategorii HL3. Przedstawiono wyniki badań na kalorymetrze meblowym przy zastosowaniu różnych źródeł zapłonu (poduszka papierowa, torba podróżnego, palnik gazowy) o mocy od 7 kW do 67 kW. Wykazały one logarytmiczny wzrost parametrów MARHE, HRR oraz TSP wraz ze wzrostem mocy źródła zapłonu. Jednocześnie stwierdzono, że maksymalne wartości HRR i TSP wystąpiły w czasie krótszym niż 4 min od zapłonu fotela, czyli w czasie bardzo istotnym dla ewakuacji pasażerów.

18

Analiza numeryczna procesu spalania w silniku HCCI z EGR zasilanym biodieslem

Jamrozik A.

Modelowanie Inżynierskie

|

2016

|

T. 28, nr 59

26--33

PL

Prezentowana praca zawiera wyniki modelowania w programie AVL Fire, jednocylindrowego, badawczego silnika z systemem spalania HCCI, zasilanego biodieslem - FAME. W silniku do sterowania procesem spalania zastosowano zewnętrzną recyrkulację spalin - EGR. W ramach pracy przeprowadzono badania wpływu recyrkulacji spalin na, istotne z punku widzenia pracy silnika, parametry, tj. kąt początku spalania, czas trwania spalania, ciśnienie w cylindrze i wartość ciśnienia indykowanego, szybkość wywiązywania się ciepła oraz emisje jednego z najbardziej toksycznych składników spalin - tlenku azotu. Dzięki przeprowadzonym obliczeniom można stwierdzić, że zastosowanie recyrkulacji spalin w silniku z samoczynnym zapłonem jednorodnej mieszanki biodiesla z powietrzem przyczynia się do opóźnienia początku spalania i znacznie wydłuża czas jego trwania. Wzrost opóźnienia spalania HCCI powoduje z kolei redukcję stężenia tlenku azotu w gazach wydechowych przy jednoczesnym wzroście ciśnienia indykowanego.

EN

The paper presents the CFD modelling results of the 1-cylinder HCCI test engine. Modelling was carried out using AVL Fire code. The test engine was powered by biodiesel-FAME fuel. The exhaust gas recirculation EGR used as factors of controlling the combustion process. The impact of EGR on the test engine parameters such as the start of combustion, combustion duration, in-cylinder pressure and indicated mean effective pressure, rate of heat release and NO emission were analyzed. On the basis of results stated that EGR for HCCI engine affects on the ignition delay and significantly increases the combustion duration. The increase in ignition delay of HCCI engine causes the reduction of NOx emission in exhaust gasses while increases the indicated mean effective pressure.

19

Determining selected diesel engine combustion descriptors based on the analysis of the coefficient of variation of in-chamber pressure

Bąkowski A., Radziszewski L.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2015

|

Vol. 63, nr 2

457--464

EN

This paper presents a method that uses the coefficient of variation (COV) of pressure in a diesel engine combustion chamber to determine the crank angle degree (CAD) for which the heat release rate (HRR) reaches the maximum value. The COV was proposed for determining the point corresponding to the angle of start of combustion (SoC). Regression models were fit with these descriptors for the engine powered by diesel, biodiesel or a combination of both, operating under full- or part- load conditions. The uncertainty parameter in these models was determined. Good agreement between the experimental results and the literature data shows the validity of the analysis.

20

Beton masywny z wykorzystaniem cementu hutniczego CEM III/B 42,5L-LH/SR/NA

Golda A., Batog M., Synowiec K., Giergiczny Z.

Budownictwo, Technologie, Architektura

|

2015

|

nr 4

52--55